System of automatic telephone-exchanges.



No. 639,l86. Patented Dec. I2,v|899.

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SYSTEM OF AUTOMATIC TELEPHONE EXCHANGES;

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No. 639,!86. Patented Dec. l2, i899.

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SYSTEM OF AUTOMATIC TELEPHONE EXCHANGES.

(Application filed may 27, 1898.) (No Model.) l5 Sheets--S hoei 4.

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SYSTEM OF AUTOMATIC TELEPHONE EXCHANGES.

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No. 639,l86. Patented Dec. l2, I899.

G. SELIGMANN-LUI. SYSTEM OF AUTOMATIC TELEPHONE EXCHANGES.

(Application filed May 27, 189B.)

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No. 639,l86. Patented Dec. l2, I899. G. SELlGMANN-LUI.

SYSTEM OF AUTOMATIC TELEPHONE EXCHANGES.

(Application filed May 27, 1898.) (No Model.)

Patented Dec. l2, l899.-

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(Application filed May 27, 1898.)

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Patented Dec. l2, I899.

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SYSTEM OF AUTOMATIC TELEPHONE EXCHANGES.

(Application filed May 27, 1898.)

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(Application filed May 27, 1898.)

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N0. 639,l86. Patented Dec. [2, I899.

G. SELlGMANN-LUI. SYSTEM OF AUTOMATIC TELEPHONE EXCHANGES. (Application film 1 May-27, 1898.)

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NlTE STATES PATENT FFICE.

GUSTAVE SELIGMANN-LUI, OF PARIS, FRANCE, ASSIGNOR TO THE AUTO- MATIO TELEPHONE COMPANY, LIMITED, OF LONDON, ENGLAND.

SYSTEM OF AUTOMATIC TELEPHONE-EXCHANGES.

SPECIFICATION forming part Of Letters Patent NO. 639,186, dated December 12, 1899. Application filed May 27,1898. Serial No; 681,916. [No model.)

To all whom it may concern:

Be it known that I, GUSTAVE SELIGMANN- LUI, gentleman, a resident of 78 Rue Mozart, Paris, France, have invented new and useful Improvements in Systems of Automatic Telephone-Exchanges, (for which an application ing combined with each group of lines as.

many such coupling devices as there are groups of lines, the arrangement and operation of these coupling devices being such that any line of any group may by means thereof be put in telephonic connection with any other line of the same or of any other group. For the purpose of enabling that coupling device to be selected which is in relation with the two groups comprising the lines between which it is desired to establish telephonic connection there is provided for each group of lines a set of operative-mechanism, (for the service of all the lines of that group,) and each line is provided with means of making connection with said mechanism. As soon as telephonic connection has been established between any two lines the said mechanism again becomes available for use, while the connection established remains undisturbed, so that several independent telephonic connections may be successively established and concurrently maintained.

In the drawings, Figure 1,Sheet 1, is a diagram illustrating in an elementary form the distribution of the coupling devices relatively to the coupling-boards at the central station, two of the lines being represented in telephonic connectiou. Figs. 2 and 2*, Sheets 2 and 3 combined, form a diagram of the electrical connections of one of the sets of mechanism at the exchange and of a coupling device. Figs. 3, 3 and 3, Sheets 4, 5, and 6,

together illustrate successi ve changes of electrical connection incidental to the operation of said mechanisms. Fig. 4, Sheet 7, is a diagrammatic perspective view of part of the coupling-boards appertainingto twogroups of lines and of certain of their coupling devices, the connections of several sets of line and service fingers being indicated, but'the electromagnetic mechanisms being omitted and telephonic connection being shown as having been established between certain of the lines. Fig. 5, Sheet 8, is a face view of a signal composing and transmitting apparatus, the front of the casing being removed. Fig. 6, Sheet 8, is a horizontal section on line 6 6, Fig. 5, the racks being raised to their full extent. Fig. 7, Sheet 8, is a vertical section on line 7 7, Fig. 5. Fig. 8, Sheet 9, is a diagram of the electrical connections of the said apparatus. Figs. 9, 10, and 11, Sheet 10, are respectively an elevation, a vertical section, and a top plan of an electromagnetic commutator forming part of a connector. Fig. 12, Sheet 10, is a plan view of the main selector, certain of the electromagnets being omitted. Fig. 13, Sheet 1O, is an elevation ofthis selector, certain onlyoftheelectromagnetsbeingshown. Fig. 14, Sheet 11, is a plan of the main distributer. Fig. 15, Sheet 11, is a plan of the distributer for returning the main distributer to rest. Fig. 16, Sheet 11, is a plan of the distributer through which is actuated the coupler selected by the main selector. Fig. 17, Sheet 11, is an elevation of part of the same distributor. Figs. 18 and 19, Sheet 12, show a face view and cross-section of a coupling-board. Fig.

20, Sheet 13, shows in part'sectional elevation the traversing-screw mechanism of a coupler. Fig. 21, Sheet 13, is a plan of the escapement mechanism controlling the traversing screw. Fig. 22, Sheet 12, is a similar view on a larger scale. Fig. 23, Sheet 13, is a part-sectional plan of mechanism which controls a selector of contact-fingers, which mechanism is also shown in sectional elevation in Fig. 20. Figs. 24 and 25, Sheet 14, are plan views of two of the sets of contact-fingers, appertaining to a coupler for making connections with a line to be called, one of the sets of fingers being shown in the operative position. The figu res also show the corresponding portions of the selector of contact-fingers. Fig. 26, Sheet 14., is a corresponding elevation, partly in section, of the same two sets of contact-fingers. Fig. 27, Sheet 15, is a plan of the mechanism of one of the sets of contact-fingers appertaining to a coupler for making connection with a line calling. Fig. 28, Sheet 15, is a side elevation, part sectional, of certain portions of the same coupler, showing two sets of contact-fingers, the one set being in the operative position. Fig. 2.), Sheet 15, is a plan view of the traversing-screw-releasing mechanism and of the mechanism for returning the said coupler to position of rest.

Similar numerals and letters of reference.

clature.

bination of signals.

By distinct signals or currents are meant signals or current emissions presenting (relatively to each other) such differences that each will influence differently the same group of receptive apparatus and by distinct combinations are meant combinations of signals differing from each other in the nature, order, or number of the constituent signals.

I designate electromagnetic com m u tator any arrangement in which a single electromagnet controls the simultaneous making or breaking of several electrical connections.

I designate connector a combination of an electromagnet and of electromagnetic commutators, whereby the calling subscribers line to which such connector appertains may be connected to selecting and manipulating mechanism allocated to the service of the group of lines to which that subscribers line belongs.

I designate particularly as distributer the known type of commutator in which connection is established between contacts arranged in two concentric circles by a brush rotated step by step. The circles may be divided into a number of equal sectors, in which pairs of contacts to be simultaneously connected occupy corresponding positions, there being as many equidistant brushes (carried by insulating-arms) as there are sectors, so that the sectors into which a distributer is divided represent so many contemporaneous cycles of operation, at the completion of which each brush passes on to position of repose at the beginning of the next sector, each brush thus taking the place of the preceding one for the next cycle, so that no retrograde motion is necessary.

By the name of selector I designate any combination of electrical and mechanical devices whereby (in response to a predetermined combination of signals) the continuity of a predetermined electric circuit is established, each selector controlling a certain n umber of electric circuits, whereof the continuity of any one is completed (to the exclusion of all the other circuits) only in response to the emission of the corresponding distinct com- Such selector (which may be variously constructed) is based on the principle that the establishment of the continuity of each of the circuits under its control depends on the suppression of a certain number of electrical or mechanical obstacles, each of the said obstacles being under the control of a different part or member of the selector, each member of the selector operating to suppress the obstacles in certain circuits and leave them in others, according to the distinct signals by which it is influenced, the complete suppression of the obstacles in a given circuit being dependent on the conjoint act-ion of the several members of the selector, which respond each in turn to the action of the signals respectively addressed to them, the presentation of these members to the action of the signals being effected by connecting these members successively to the calling line through the medium of a distributer.

By coupling device is meanta pairof electrically-conjoined apparatus termed couplers, the two couplers of a pair being respectively designated the called-line coupler and the calling-line coupler, the former being adapted to make connection with the line of a subscriber to be called and the latter to make connection with the line of the subscriber calling and so to complete the direct telephonic connection between those two lines. i

For the purposes of this system there is provided at each subscribers station a signal composing and transmitting device for determining the nature, order, and number of signals sent in making a call.

The apparatus at the central station is as follows, viz:

(a) A connector (at the extremity of each line) whose function is to establish (between the line to which it appertains and the selecting and manipulating mechanism common to the group to which the line belongs) a temporary electrical connection, which is broken automatically when the manipulation is completed.

(b) A single set of selecting and manipulating mechanism (for the common service of the lines of a group) by which the coupling devices are actuated. This mechanism comprises a main distributer, a main selector, a manipulator, and return-to-rest devices, the functions of these elements being as follows: By the main distributer the various members of the selector and the manipulator are successively connected to the line calling. By the main selector the subscriber calling is enabled to select a particular coupling device. By the manipulator the signals sent by the subscriber calling are translated into local currents, which are transmitted to the coupling device selected. By the return-to-rest devices the connector of the line which has made or attempted to make a call and like wise the main distributor and the main selector used for that purpose are automatically returned to their initial position when done with.

(c) A pair of coupling-boards, the one being used when a line upon it is to be called and the other being used when a line upon it is calling. Upon each coupling-board appear (in the form of contact wires or pieces) the two wires of eachsubscribers line of the group to which the board belongs, and also a local service-wire for each line,the service-wires appertainingto the sameline on the twoboards of a pair being quite distinct. In each board the service-wire and the line-wires appertaining to a subscribers line are arranged in ahorizontal row and in regular order from front to back of the board, while the rows of wires appertaining to different subscribers of the group are superposed, there being, for instance, five rows (superposed at regular intervals) appertaining to five different subscribers and then a vacant space, then five more rows appertaining to five other subscribers, and so on. In practice the two coupling-boards of a pair would be combined in one, and it is to be understood that wherever I refer to coupling-boards I mean to also include the idea of using a single board comprising two members, and vice versa.

(61) Coupling devices for the use of each group of subscribers lines, there being duplicate, triplicate, or more sets of such coupling devices for each of the circuits controlled by the main selector. Each-coupling device is composed of two members termed couplers, of which the corresponding parts are in electrical connection with each other, one of said members, termed the called-line coupler, being used for making contact with the line to be called, the other member, termed the calling-line coupler, serving for making contact with the line calling. All the calling-line couplers appertaining to the lines of the same group are side by side in front of the calling-line coupling-board of this group, whereas the called-line couplers appertaining to these same coupling devices are distributed, one in front of each of the called-line coupling boards of different groups of lines. Consequently when a subscriber desires to make a call there will always be available a coupling device (among those controlled by the main selector and the manipulator of his group) whereof the calledline coupler is in front ofthe called line coupling-board on which the line to he called appears, while the associated calling-linecoupler is situated in front of the calling-line coupling-board on which appears the line of the subscriber calling, only the called-line coupling-board of the line called and the callingline coupling-board of the line calling being used. The called line and calling-line coupling-boards are in practice combined in one, the line-wires being common to both and the two service-wires being distinct, the calledline couplers being placed at one face of the board and the calling-line couplers at the other face. Telephonic connection will be established when the called-line coupler has made contact with the line of the subscriber called and the calling-line coupler has also made contact with the line of the subscriber calling. This position of conversation is illustrated in Fig. 1 in respect of the line L* L of a calling subscriber in group I and the line L* If of the called subscriber in group V. To accelerate the making of. connection with the line to be called, the called-line coupler has several sets of contact fingers, of which one set only is used, the other sets being rendered (or left) inactive by means ofa selector of contact-fingers, the coupler being so moved as to bring the set of contactfingers to be used opposite the line to be called and that set being selected by mechanisms actuated in succession through the medium of a distributer.

(e) Return-to-rest devices, which enable the coupling device which has been used to be returned to its initial position when done with.

Before giving a detailed description of the circuits and mechanisms it is necessary to choose a particular type oftelephonic linewire system and apparatus, because the number of distinct signals available for use differs according as the lines of the system have an earth-return or complete metallic circuit and according as it is oris not permissible tolocate at each subscribers station batteries capable of furnishing the operative currents or signals. Consequently upon the number of distinct signals available depends the arrangement of the signal-composing device and likewise the arrangement of the selectors by which the diversity of these distinct signals is utilized. I will therefore take as example a two-wire system and suppose that the batteries furnishing the operative currents or signals and even the battery which serves for conversation are (for each group of subscribers) concentrated at thecen tral station to which the lines of the group converge; but the modifications involved if another example be chosen do not materially affect the system.

In a central-battery system the manipulation of high resistances at the station of the subscriber calling enables three sorts of distinct signals to be obtained-viz. current through the one wire earthed without. resistance at the subscribers station, current through the other wire earthed without resistance at the subscribers station, and current through both wires connected in series without any resistance being interposed between them and without being earthed at the subscribers station. It is only necessary that the battery be put to earth by its middle at the central station. I will first suppose that a main selector having two members will sufflce, and I will afterward show 110w a greater number of subscribers lines could be provided for. i

In order to prevent erroneous combinations of signals, a signal composing and transmitting device such as shown in Figs. to Sis pieces 155 156.

used. It consists of fixed and adjustable contacts and a double brush 164 165, movable in guides 163. Six vertically-sliding racks 141 142 143 144 145 146 when raised engage with pins 151 on a horizontal slide-bar 150. Five of the racks carry tablets 141 142 143 145 146, each of which bears contact-pieces, hereinafter described, and a column of numbers, the adjustment of each rack determining which of its contact-pieces are brought into the path of the contact-brush 164. The rack 144 carries two spring-fingers 152 and 153, which, according to the adjustment of this rack, make contact, respectively, with fixed contact-pieces 154 155 or with fixed contact- It also carries a shutter 157, having two apertures arranged diagonally and situated in front of the double column of figures on the tablet 143. ing carries a conductive strip 158, fixed in the path of the brush 165, this strip 158 being interrupted by a gap 158 opposite to the contact-pieces 187 188 189 190 and 191 192 193 194, carried by the racks 145 and 146. The front of the casing has a slot 159 for the handle 160 of the double contact-brush, a slot for the handle 162 of the sliding bar 150, and five windows 141 142 143 145 146 opposite the columns of figures carried by the correspondingly-numbered tablets. According as rack 144 is adjusted the one or other aperture of its shutter 157 coincides with the one or other half of the window 143, so that the column of figures opposite the other half is masked. The double brush 164 165 is normally held toward the rightfor instance, as shown by a weight connected to it by a cordso that the block which carries the brush presses the spring 166 against the spring 167. When at the other end of its course this block presses the spring 168 against the spring 169 and is retained by a detent 170, as shown dotted in Fig. 5. On the bar 150 is a block 171, having a handle 162 and free to be slid upon the bar 150 to an extentlimited bya stop 174,so that when the handle is moved to the right the block alone will be moved at first, and by means of a stud 171 it will cause a springcontact 172 to bear against a contact 173. When the block meets the stop 174, the sliding bar 150 is moved also, whereby the pins 151 are disengaged from the racks and a pin on the bar 150 acts on the detent 170, so as to release the contact-brush 164 165 and allow it to be returned by the weight to normal position. To allow of the rack teeth slipping past the pins 151 when the racks are raised, the pins are spring-pressed into engagement with the rack-teeth by leaf-springs carried on bar 150.

The contacts carried by tablet 141 cornprise a plain conductive strip and also a comb -like plate 184, having four contactlimbs of lengths so graduated that one or more of said limbs will be presented in the path of The front of the casbrush 164, according to the adjustment of the rack 141, The tablet 142* carries plain strips 181 182 and between them a comb-like plate 185, having three contactlimbs of lengths so graduated that one or more of said limbs will be presented in the path of the brush 164, according to the adjustment of rack 142. The tablet 143 carries a graduated comb-like plate 186, having five limbs, whereof the number presented in the path of the brush 164 depends on the adjustment of rack 143. It also carries a plain strip 183. The plain strips 180 181 182 183 are at least of such length as to be respectively presented in the path of the brush 164 along with any one or more limbs of the comb-like contact-plate carried by the same tablet. The tablet 145 carries a vertical row of contacts 187 188 189 190, separated by narrow spaces whose width is less than the width of the brush 164 and whose relation to the teeth of the rack 145 is such that when the rack is adjusted two of the contacts will always be presented together in the path of the brush 164, which thus establishes on its passage connection between the two contacts so presented. The'tablet 146 carries a similar row of contacts 191 192 193 194 and also a plain contact-strip 195.

The two wires L L of the subscribers line are connected, L to the contact-plate 155 and L to each of the two contact-plates 154 156. Strips 181 182 183 are connected to the springfinger 153, and the comb-like pieces 184 186 are connected to the other spring-finger 152, so that the relative connections of the line-wires L and L with the sets of contacts 181 182 183 and 184 185 186 will depend on the adjustment of rack 144. On the other hand, the connections of the small contacts 187, 188, 189, and 190 and those of the similar contacts 191 192 193 194 and that of the contact 195 are not capable of reversal and are as follows: 188 192 195 are connected to the line-wire L, 189 193 to the line-wire L and 187 190 191 194 and the two parts of the contact-strip 158 (shown at top of Fig. 8) are connected to earth. Normally the wire L is earthed through 166 167, through the telephone-bell 199, the high resistance 196, and an indicator 197; but as soon as the brush 164 165 is moved by handle 160 contact is broken at 166 167 and the wire L is isolated. When the brush-block presses the spring 168 against 169 and when the telephone-receiver is taken off the hook, the line-wire L is put to earth through the conversation apparatus 198, the high resistance 196, and the indicator 197. Lastly, of the two springs 172 173 (shown at the top of Fig. 8) the latter is permanently to earth and the former is connected to the contacts 181 182 183, in whose reversals of connection it participates.

The operation of the signal composing and transmitting device is as follows: Normally the line-wire L is isolated, and the line-wire L is to earth through a resistance of from one thousand to two thousand ohms. As soon IIO - 01 not.

as the subscriber after having adjusted the racks begins to move the brush 164 165 the wire L is also isolated. Then the following effects are produced in succession:

First. A signal of invariable kind is sent over a grounded circuit, the wire L being put to earth when the double brush 164 165 passes over the contacts 195 and 158, the line being again isolated when the brush 164 quits the contact 195.

Second. A signal is sent which is variable in kind, according to the adjustment of the rack 146, the effect (according as the brush 164 passes over the two contacts 191 192 or over the two contacts 192 198 or over the two contacts 193 194) being respectively to put Wire L to earth without resistance or to connect wires L L in series without resistance and without earth, or to put line L to earth without resistance, the effect being followed in either case by isolation.

Third. A signal is sent which is variable, according to the adjustment of rack 145, (the possible nature and effect of the signals being the same as described in the previous paragrapln) followed by isolation. D

Fourth. According to the adjustment of rack 144 the strips 181 182 183 are either connected to the line-wire L and the graduated comb-shaped contacts 184 185 186 are connected to the line-wire L or, inversely, the signals being as next described under 0t orb, as the case maybe. (a) The wire L is earthed once, and the wire L is earthed a variable number of times, according to the adjustment of rack 143. Wire L is earthed a second time, and the wire L is earthed a variable number of times, according to the adjustment of rack 142. The wire L is earthed a third time, and the wire L is earthed a variable number of times, according to the adjustment of rack 141, the brush being finally engaged by detent 170; (b) or inversely, as regards the respective effects produced on the lines L L I will suppose that wire L was connected with the strips 181 182 183 and wire L with the graduated comb-shapedcontacts 184 185 186. When the double brush 164 165 reaches the end of its course, all the signals necessary foractuating the connector, the main selector, and the manipulator will have been sent, and the calling subscriber has only to listen at his receiver in order to ascertain (by the absence or presence of a buzzing or musical sound) whether the line of the subscriber to be called is disengaged IVhatever may be the result of this test, the calling subscriber then moves the handle 162 toward the right, thereby first pressing spring 172 against 173, and so sending a final signal similar to those sent by the passage of the brush over plates 181182 183 i. c., by hypothesis, putting line-wire L to earth-the further movement causing the bar 150 to release the double brush and the racks. The racks then fall, and the'brush is returned to its initial position by the weight.

To prevent too rapid or irregular motion of the brush and consequent malformation of the signals, the speed of its forward motion may be controlled by any suitable retarding means. The telephone transmitter, receiver, and hell are as usual, except that the spring 200, actuated by thehook-switch 201, whereby the transmitter-battery is ordinarily thrown in or out out, now connects or isolates the linewire L Since for each adjustment of a rack a certain figure is exhibited at the corresponding window, then if the distinctive number of each subscriber corresponds with the group of figures exhibited when the racks are adj usted for calling that subscriber it will follow that it is only necessary in order to call a certain subscriber to so adjust the racks as to exhibit his distinctive number and then to move the double brush from end to end of its course. Ihe telephone-receiver will then indicate by silence or by the noise heard whether the line wanted is disengaged or not, and the final signal completes the manipula-v tion for establishing communication or returns all the parts to rest, as the case maybe.

Before describing the mechanism and circuits at the central station it will be convenient to refer to Fig. 1, which illustrates in an elementary form the distribution of the coupling devices with regard to the couplingboards at the central station, the subscribers lines being supposed to be divided into six groups I II III IV V VI, each group compris ing any number of lines, but only a few be- .ing indicated.

1 11 III IV V VI are the calling-line coupling-boards, and I II III IV V VI. are the called-line coupling-boards, pertaining to the several groups, the wires of each line of a group appearing on both boards and a distinctservice-Wire being provided for each line on each board.

1 2 3 4 5 6 represent diametrically by lozenges the calling-line couplers, and 1 2 3 4 5 6 represent by rectangles the called-line couplers, each such coupler being supposed for the sake of simplicity to have only one set of fingers for making contact with the line and service wires on the coupling-boards, the line-fingers alone being indicated, together with the corresponding speakingcircuits. The line-fingers of each calling-line coupler are electrically connected each to the corresponding finger of the associated called-line coupler, the couplers being associated as follows: by coupling the fingers of 1, group I, to the fingers of 1", group I; the fingers of 2 group I, to the fingers of 1 group II; the fingers of 3", group I, to the fingers of 1 group III, and so on; the fingers of 1, group II, to the fingers of 2*, group I; the fingers of 2, group II, to the fingers of 2, group II; the fingers of 3, group II, to the fingers of 2 group III, and so on.

L L are the subscribers lines, those which are in telephonic connection being (listin- IIO 

